1. Field of the Invention
The present invention generally relates to a disk cartridge, and more particularly to a technical field for making it possible to discriminate a disk cartridge easily at a stage before the insertion of the whole of the disk cartridge into a disk drive apparatus by forming a discrimination groove on the outer shell of the disk cartridge for performing discrimination of the disk cartridge from other type ones.
2. Description of the Related Art
There is a type of a disk cartridge including an inner shell supported to slidably rotate in the inside of an outer shell, shutter members supported to slidably rotate on the inner shell, and a disk-shaped recording medium rotatably housed in a housing space formed between the inner shell and the outer shell. As the inner shell slidably rotates against the outer shell, the shutter members are slidably rotated to open or close an opening portion of the outer shell (see, for example, Japanese Laid-open Patent Application No. 2001-332058A).
Some of the above-mentioned disk cartridges are designed to have substantially the same outside dimensions, even if the disk cartridges are different types from one another, for realizing low prices by commonly using parts.
As these disk cartridges designed to have substantially the same outside dimensions, there are, for example, rewritable disk cartridges and write once-type disk cartridges corresponding to the rewritable disk cartridges, the rewritable disk cartridges and read only memory type disk cartridges corresponding to the rewritable disk cartridges, disk cartridges meeting with the standards for consumer use and disk cartridges meeting with the standards for professional use corresponding to the disk cartridges meeting with the standards for consumer use, and the like.
However, in such different types of disk cartridges designed to have the same outside dimensions, when a user tries to insert one type of disk cartridge among the disk cartridges into the insertion opening of a disk drive apparatus, there is the possibility that the user erroneously inserts the other type of the disk cartridge into the insertion opening of the disk drive apparatus because the outside dimensions are substantially the same.
Accordingly, some types of the disk drive apparatus are configured so as to read the identification (ID) recorded previously on a disk-shaped recording medium of the disk cartridge to eject the other type of the disk cartridge when the above-mentioned erroneous insertion is done.
However, when such a disk drive apparatus ejects the erroneously inserted disk cartridge upon reading out the ID as described above, the recognition of the erroneous insertion is not performed until the reading operation of the disk-shaped recording medium of the inserted disk cartridge is performed. Consequently, it is needed to take a time until the disk-shaped recording medium of the disk cartridge is mounted on the disk table of the disk drive apparatus, a time for performing the reading of the recorded ID, and a time for performing the ejection of the disk cartridge from the disk drive apparatus, and then a user must wait for so much time until the user can use one type of the disk cartridges. Hence, the disk drive apparatus has a problem that the usability of the apparatus is not so good.
Moreover, the identification information (ID) indicating whether the type of a disk cartridge is one type or the other type is recorded on the disk-shaped recording medium. Consequently, when an alteration or the like of the recorded identification information is performed, for example, at the time of reconstruction or the like of recorded information, the disk drive apparatus cannot judge at all which type of the disk cartridge the inserted disk cartridge is. Such a situation has the possibility of causing various disadvantages such as illegal processing of information recorded on the disk-shaped recording medium, damage of the recorded surface of the disk-shaped recording medium by being irradiated by a laser beam having power not corresponding to the recording medium, and a breakdown of an inside mechanism of the disk drive apparatus.
On the other hand, in some types of disk cartridges designed to be substantially the same, for achieving the improvement of a transfer rate and the improvement of the workability of editing work and the like, the opening portion of the outer shell of one type of the disk cartridges is configured to be larger than that of the other type of the disk cartridges, and the disk drive apparatus corresponding to the other type of the disk cartridges is provided with two optical heads (optical pickups) to be configured in order that the two optical heads may be arranged to be opposed to a disk-shaped recording medium with an opening portion put between the two optical heads at the same time when the disk-shaped recording medium is mounted on a disk table.
Then, when one type of the disk cartridges is inserted by mistake, one of the optical heads escapes for avoiding the contact of a part of the disk cartridge where the opening portion is not formed with the optical head. However, the disk drive apparatus needs a space for the escape of the optical head, and becomes larger in size by the space.